Rotary electric contact maker



Patented Sept. 2, 1941 UNITED STATES PATENT OFFICE Application September 28, 1938. Serial No. 232,139 In France October 20, 1937 3 Claims.

The present invention relates to a rotary electric contact-maker for all applications and is characterised by the fact that it is constituted by a rotary conducting member which is in contact simultaneously with one of the plane faces of two circular conducting rings one of which is continuous and the other of which is constituted by an appropriate number of suitably arranged sectors.

The present invention also extends to a certain number of detail objects forming a part of the main object, applied separately or in any combinations.

1. The two circular conducting rings are rendered rigid, preferably upon moulding, with an insulating member.

2. The gaps provided in one of the conducting rings are obtained by forming suitable slots in said ring, by means of a milling cutter, saw or the like 3. .The rotary conducting member is mounted on the shaft for actuating the contact-maker through the medium of a resilient insulating member so that said member is in resilient contact with the conducting rings.

4. The contacts between the rotary member and the conducting rings are ensured by rollers journalled on spindles provided at the ends of said rotary member.

5. The continuous conducting ring and the various segments of the other ring each comprise a connection terminal, said terminals being respectively connected to the contact-pieces of the device or apparatus controlled by said contactmaker.

6. The insulating member on which are secured, upon moulding, the conducting rings, is frictionally mountedon a fixed hub so as to be angularly adjusted.

7. The angular adjustment of the insulating member is obtained by means of a toothed pinion meshing with a toothed disc rigid with said member, an indicating member, such as an index rigid with said member and movable opposite a suitable fixed graduation, allowing of facilitating this adjustment.

8. The shaft on which the rotary conducting member is rigidly secured, is constituted by the indicating shaft of a measuring apparatus controlling the operation of the contact-maker.

The invention also extends to the application of the rotary electric contact-maker previously defined to measuring apparatus (ordinary tachymeters, or tachymeters utilised in particular for controlling the pitch of a variable 'pitch airscrew) and, in general, to apparatus adapted to ensure an automatic control.

The present invention also includes a certain number of particular points which will appear in the following text, with reference to the accompanying drawing, given by way of example only, in which: 1

Fig. 1 is an axial section of a form of construction of an electric contact-maker made according to the invention.

Fig. 2 is a plan viewcorresponding to Fig. l, the dial and the upper platen being removed.

The electric contact-maker according to the invention is constituted by a fixed hub I supported by a platen 2 or the like. In an axial perforation formed in said hub is joumalled the shaft 3 for actuating the contact-maker, said shaft 3 being angularly movable from the member or apparatus controlling the operation of said contact-maker.

On the fixed hub I and resting on a flange I provided at the lower part of said hub, is fitted a disc 5 toothed at its periphery for the purpose explained later on. On saiddisc 5 is secured, by screws 1 or the like, a member 8 made of insulating material and for instance of moulded material, at the upper part of which are concentrically secured two circular conducting rings 8 and 9. In an embodiment which for the moment appears advantageous, these two rings 8 and 0 are secured to the member 8 when moulding the lat ter. For that purpose, the outer ring 8 comprises, at its lower part, a dove-tail member 8 or the like the lower face of which is preferably milled for avoiding any slipping between the ring 8 and member 8. Likewise, the inner ring 9 comprises, on its inner face, a groove 9* in which enters the moulded material which thus prevents the ring 9 from disengaging from the moulded material. In a similar manner and in view of avoiding any slipping of said ring 9 relatively to member 6, one at least of the faces of said ring 9 embedded in said member 8 is milled, for instance.

The member 6 is clamped on the fixed hub I by a washer III secured on the upper face of hub I by screws II or the like. In this manner it will be seen that member 8 and disc 5 rigid therewith rotatively move relatively to the hub I only in antagonism to the friction exerted by the washer I II On the upper end of shaft 3 is secured, by a locking screw I2 or the like, a hub it which is rendered rigid, by all suitable means and for instance by beading, with a disc I4 made of slightly resilient insulating material, such as Bakelitecoated canvas. Two arcuate recesses I! are provided in the disc I 4. Said recesses which are symmetrical relatively to the vertical plane passing through the axis or the rollers 23 and 24. as illustrated in the accompanying drawing, increase the flexibility of the marginal parts of said disc on either side of said vertical plane. v

At right angles to this aids, the disc I4 comprises at its periphery two diametrally opposed lugs I6. On said disc I4 is secured, by rivets I I or the like, engaged in perforations I8 formed in the lugs I6, 9. metal flange I9 provided with two diametrally opposed arms 20 and M and the ends of which are bent at 90 degrees, the one, 20,

ratus through the medium of a gear mechanism or the like.

The invention also includes the application of the rotary electric contaet-maker to measuring apparatus adapted to ensure a control and particularly an automatic control. 4

According to the invention, thiscontact-maker is applicable to tachymeters and particularly to tachymeters used for controlling the pitch of a variable pitch airscrew.

As a certain torque is nevertheless indispensable and as the tachymeter is often placed rather far from the engine, it is necessary to use.

for said tachymeter, an electric transmission. In fact, the flexible members generally usedas transmission means give shocks and vibrations 9 is continuous and is connected, through the medium of a lateral pin screwed in said ring, to one of the terminals of the device controlled by the contact-maker. The other ring 8, on the contrary, presents gaps, provided in suitable number and which are formed preferably after the manufacture of member 6 in which are embedded upon moulding, the rings 8 and a. For that purpose, in ring 8 and throughout its section, can be formed, by means of a milling cutter, a saw, or the like, slots 26 which may subsequently be filled with a suitable insulating material in order that the upper surface of said ring should remain plane without notches. On each of the segments of ring 8 and laterally thereto is secured, by screwing for instance, a pin 21, the various pins 2'! being connected to the various terminals of the device controlled by the contactmaker.

It will be easily understood that, according to the position of the roller 23 which itself depends on the position occupied by shaft 3, an electric circuit will be established through one or the other of the segments of ring 8. a

In order that the position of the segments of ring 8 can be initially adjusted, relatively to the fixed hub i, the toothed disc 5 meshes with a toothed pinion 28 provided on a rod 29 journalled, on the one hand, in the fixed platen 2 and, on the other hand, in a second fixed platen 3G. On the lower face of disc 5 can be secured an index or the like 3| movable opposite a suitable graduation and adapted to facilitate the adjustment of the member 5 carrying the rings 8 and 3.

It will be understood that such a contactmaker can receive numerous applications in all 'cases where it is desired to control, from the angular position or a shaft, the operation of various devices. It is thus, in particular, that such a contact-maker can be used in combination with an indicating apparatus, such as a tachymeter for instance, in order to obtain the closing of various electric circuits according to the value of the speed measured by said tachymeter, said electric circuits serving for the control of all suitable devices and for instance, for the automatic control of the pitch of aerial propellers. The shaft 3 can be directlyconstituted by the shaft of the tachymeter, case in which an indicating pointer, not shown, will be secured on its upper end so as to be movable opposite a suitable dial secured on the platen 30. Said shaft 3 might and cannot be used in the case of a tachymeter for controlling the pitch of a variable pitch airscrew. Use can particularly be made of the apparatus described and illustrated in the United States Patent No. 2,097,215 dated December 6, 1933.

The present invention is not limited to the form of construction described and illustrated, but includes all those comprising the characteristic features above set forth and allowing to obtain the desired result.

-What I claim as my invention and desire to secure by Letters Patent is:

1. In a rotary electric contact-maker comprising a frame provided with a central annular cy-" frame on which said support can rotate, a resiiient insulating member secured on said central shaft, a rotary conducting element mounted on said insulating member, two rollers journalled at two opposite points on said conducting element and adapted to respectively press on the first ring and on the second ring when the central shaft is rotated, and means for rotatively moving said support for adjusting the position of said rings.

2. In a rotary electric contact-maker, in combination, a frame provided with a central annular cylindrical projection for constituting a hearing, a shaft journalled in said bearing, an insulating support provided with an axial bore and Journalled on the cylindrical projection of the frame, means for frictionally connecting said projection and said support, a first continuous conducting ring mounted on the insulating support, a second conducting ring consisting of a plurality of segments electrically insulated and also mounted on said support, said rings being co-axial with said shaft, a resilient insulating member secured on said central shaft, a rotary conducting element mounted on said insulating member, two rollers journalled at two opposite points on said conducting element and adapted to press respectively on the first ring and on the second ring when the central shaft is rotated, means for rotatively moving said support for adjusting the position of said rings, and an indicating pointer rigid with the support for indicating the position of adjustment of said support and consequently of said rings. v

3. In a. rotary electric contact-maker as be driven from the shaft of the indicating appaclaimed in claim 2, the rotary conducting element is provided with a central perforation so as to which is secured to the insulating member at pivot about said central shaft and the resilient two opposite points the geometrical junction line insulating member is provided with two arcuate or which is perpendicular to the vertical plane ports asymmetrically arranged on either side of passing through the axes of the rollers.

the vertical plane passing through the axes of the 5 rollers journalled on the conducting element CHARLES HlLAIRE HENRI RODANET. 

